A known fuser, for example, as disclosed in JP2010-231008A, includes a heat roller, a pad member that nips an endless belt in cooperation with the heat roller between the pad member and the heat roller and serves to form a nip portion between the heat roller and the endless belt, and a holding portion that holds the pad member. The pad member includes a pressurizing pad that contacts the endless belt. The pressurizing pad is attached to a supporting plate. The pressurizing pad attached to the supporting plate is mounted in a recess in the holding portion, thereby holding the pad member in position relative to a moving direction of the endless belt at the nip portion.